Engraving gold/nickel plated dog tags with CO2 laser and cermark/thermark?

[Anne Sullivan]

I am pretty new to laser engraving. I'm using a 50w Epilogue Helix at my local makerspace. For Christmas I'd like to make some keychains for family members. So I bought some Cermark 6018 metal marking tape and these gold and nickel clad dog tags from chewbarka:

https://www.chewbarka.net/goldnickel...clad-p-72.html

I set the laser to 5% speed, 100% power. My design came out great on a piece of stainless steel scrap metal. But when I tried to engrave the dog tags, the cermark washed almost entirely off, leaving just a very faint ghosted image. I have a bunch of questions, and I would really appreciate any input anyone has.

First, has anyone gotten the cermark metal marking tape to work with gold or nickel clad items like this? If so, do you have any recommendations on what I could do differently to make it work? Is there some way I should be changing the substrate, applying the tape, changing the speed/power settings, etc?

Second, has anyone gotten other cermark/thermark products to work with this type of finish? If so, is there a different product you'd recommend? I see that cermark 6038 is recommended for smooth and polished metals. And the thermark site says it recommends thermark LMM14 over 6038. Does anyone know if one of these would actually work better?

Third, are there other products that you'd recommend instead? I see that chewbarka also has "satin finish" stainless steel dog tags, and laserbits has stainless steel dog tags. I'd prefer something with a nice finish, since this is for a gift, but I understand that smooth finishes might be causing my problems.

Thanks so much for any thoughts you might have!

[Kev Williams]

I've gotten cermark to work great on stainless steel, various plain steel, *pure* nickel, and titanium. I can barely get it to stick to brass, but even then it MUST be clearcoated or 90% of it can be washed off with water. Polished stainless works great, IF you can keep the cermark on it. The finish is so slick that once the cermark is REALLY dry it'll fall right off.

What has NOT worked whatsoever, for me anyway, is gold, silver, raw 6061 aluminum, nickel *plated* items, or chrome. Also, "naval" brass doesnt' work, mostly because it's not brass, it's bronze.

I've never tired 50 or 70 series aluminum. I have tried clear anodized aluminum, with inconsistent results.

[Anne Sullivan]

Thanks so much, Kev, that was very helpful!

I am going to try the "satin finish" stainless steel dog tags from Chewbarka next.

You mentioned that getting the cermark to stay on is a problem--have you ever tried the Cermark 6038? It's supposed to be designed for high-polished surfaces, to "create a uniform film":
http://www.thermark.com/content/view/39/78/

But it's pretty expensive, so I'd love to hear if it's worked for others before I order some.

[Mike Null]

The tags you have are made of aluminum. I have always had difficulty with Cermark and aluminum to the extent that I do not offer it. The anodized aluminum tags look quite good when engraved and you might have some luck with the ss tags. The tape requires higher power as I recall though you should have enough at 50 watts.

[Kev Williams]

Only Cermark I've ever used is the LMM6000 stuff. What I do to help keep it on polished SS is to spray some Windex or Fantastik or whatever on, then lightly wipe it off, so some of the residue stays on. Not perfect, but the Cermark does hang on better-

[Dan Hintz]

Any coating on those tags to keep them nice and shiny over the years? If so, it needs to be removed before Cermarking.